{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'.a'"
      ]
     },
     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "url='julyedu.ai' \n",
    "url[-3:-1]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'hh'"
      ]
     },
     "execution_count": 6,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "'h'*2"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([2, 3, 4])"
      ]
     },
     "execution_count": 10,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "import numpy as np\n",
    "l = np.array([1,2,3])\n",
    "l+1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[1, 2, 3, 1]"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "l+[1]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "'x'"
      ]
     },
     "execution_count": 11,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "'x' or 'y' or []\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "{1: 3, 2: 3}"
      ]
     },
     "execution_count": 12,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "{}.fromkeys((1,2),3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [
    {
     "ename": "TypeError",
     "evalue": "'str' object does not support item assignment",
     "output_type": "error",
     "traceback": [
      "\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
      "\u001b[1;31mTypeError\u001b[0m                                 Traceback (most recent call last)",
      "\u001b[1;32me:\\CHH3213_KING\\研究生\\导师\\就业规划\\自动驾驶\\chhRobotics\\PathPlanning\\Reeds-Shepp曲线\\test.ipynb Cell 7'\u001b[0m in \u001b[0;36m<cell line: 2>\u001b[1;34m()\u001b[0m\n\u001b[0;32m      <a href='vscode-notebook-cell:/e%3A/CHH3213_KING/%E7%A0%94%E7%A9%B6%E7%94%9F/%E5%AF%BC%E5%B8%88/%E5%B0%B1%E4%B8%9A%E8%A7%84%E5%88%92/%E8%87%AA%E5%8A%A8%E9%A9%BE%E9%A9%B6/chhRobotics/PathPlanning/Reeds-Shepp%E6%9B%B2%E7%BA%BF/test.ipynb#ch0000007?line=0'>1</a>\u001b[0m a\u001b[39m=\u001b[39m\u001b[39m'\u001b[39m\u001b[39m123\u001b[39m\u001b[39m'\u001b[39m\n\u001b[1;32m----> <a href='vscode-notebook-cell:/e%3A/CHH3213_KING/%E7%A0%94%E7%A9%B6%E7%94%9F/%E5%AF%BC%E5%B8%88/%E5%B0%B1%E4%B8%9A%E8%A7%84%E5%88%92/%E8%87%AA%E5%8A%A8%E9%A9%BE%E9%A9%B6/chhRobotics/PathPlanning/Reeds-Shepp%E6%9B%B2%E7%BA%BF/test.ipynb#ch0000007?line=1'>2</a>\u001b[0m a[\u001b[39m0\u001b[39m]\u001b[39m=\u001b[39m\u001b[39m4\u001b[39m\n",
      "\u001b[1;31mTypeError\u001b[0m: 'str' object does not support item assignment"
     ]
    }
   ],
   "source": [
    "a='123'\n",
    "a[0]=4"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "[3, 2, 1, [...]]"
      ]
     },
     "execution_count": 15,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "lst = [3, 2, 1]\n",
    "lst.append(lst)\n",
    "lst"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "inf"
      ]
     },
     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "a=float('inf')\n",
    "a\n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 3.8.12 ('gobigger')",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.8.12"
  },
  "orig_nbformat": 4,
  "vscode": {
   "interpreter": {
    "hash": "0c7484b3574347463e16b31029466871583b0d4e5c4ad861e8848f2d3746b4de"
   }
  }
 },
 "nbformat": 4,
 "nbformat_minor": 2
}
